Question: $-\dfrac{9}{4} - \dfrac{3}{2} = {?}$
$ = - {\dfrac{9 \times 1}{4 \times 1}} - {\dfrac{3 \times 2}{2 \times 2}} $ $ = - {\dfrac{9}{4}} - {\dfrac{6}{4}} $ $ = - \dfrac{{9} - {6}}{4} $ $ = -\dfrac{15}{4}$